If you usually deal with complex mathematical functions and looking for a free and powerful software tool that lets you create scientific plots and graphs easily, then ‘Veusz’ will come in handy for you (doesn’t support 3D plots though).
It’s an open source tool, runs on multiple operating systems (GNU/Linux, Mac OS X and MS Windows) and lets you save the plots into PDF, JPEG, BMP, PNG, SVG and few other popular formats as well.
To be honest, I’m a bit of an alien when it comes to these type of tools thus I cannot go into all the details. But, even for someone like me could see the power of ‘Veusz’ (lots of features, ease of use etc) so I thought someone would find it useful which is the reason I decided to write about it anyway :).
With ‘Veusz’ you can either start from scratch or if you have saved data then you can import those from CSV or other file formats into the main window and can customized the X/Y axis, add other data (images, key, labels, page, grid etc), and mathematical functions, Undo/Redo, Zoom in/out, use built in ‘operations’ for editing the existing data (add, subtract, split, join, add filters/expressions etc), read data points from graphs, change fonts & colors … are just a few to mention.
‘Veusz’ uses widgets while creating plots so you can easily add/delete individual sections of a plot with ease (different widget for X/Y axis, graphs, images etc).
If interested, please download it from this page (the GUI seems to be a bit buggy, but it’s way better than using some of those command-line tools, wouldn’t you say? :)). Good luck.